(A) study on active collision avoidance system for the road vehicle via automated lateral control

Abstract

According to a recent official survey, over 10,000 people are killed annually in the traffic accidents in Korea and most of them are known to be caused by some mistakes of the drivers. Therefore, more active safety measures, such as collision warning/avoidance systems, are needed so as to accommodate the mistakes of the drivers. Collision warning systems basically assist the driver when he/she makes an error such as improper looking, misjudgment, drowsiness, control miss upon facing a collision. However, there is a doubt on whether the driver, who makes such an error, can carry out a proper evasive maneuver immediately after a warning in an emergent situation. There is also another doubt on whether the driver reacts to a wrong way by taking advantage of the warning system and thus reduces the safety margin against crashes. A great deal of effort has been concentrated on the longitudinal control for the collision avoidance of the road vehicles. In an emergency as well as in a normal situation, however, the steering control can be a very effective alternative as observed in the practice of manual evasive driving. In the reported methods of emergency lateral control, it is found that the dynamic motions of the neighboring vehicles are often ignored, which may result in some danger of $2^nd$ collision. Therefore, it is necessary to assess the surrounding traffic situation to prevent $2^nd$ collision that can occur just after escaping from the 1st collision situation. In this thesis, the collision avoidance problem of the road vehicle is formulated to cope with the dynamic situations caused by the neighboring vehicles. Specifically, a hierarchical control scheme is suggested as a feasible solution. It can be divided into three sub-problems that comprise a layer in a hierarchy. In designing the overall system, we start from the vehicle kinematic model. From the characteristics of the vehicle, path is designed for the controlled vehicle to track with little tracking e...